package com.google.gson.internal.bind.util;

import static com.google.common.truth.Truth.assertThat;
import static org.junit.Assert.assertThrows;
import static org.junit.Assert.fail;

import java.text.ParseException;
import java.text.ParsePosition;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Locale;
import java.util.TimeZone;
import org.junit.Test;
import org.junit.function.ThrowingRunnable;

public class ISO8601UtilsTest {

    private static TimeZone utcTimeZone() {
        return TimeZone.getTimeZone("UTC");
    }

    private static GregorianCalendar createUtcCalendar() {
        TimeZone utc = utcTimeZone();
        GregorianCalendar calendar = new GregorianCalendar(utc);
        // Calendar was created with current time, must clear it
        calendar.clear();
        return calendar;
    }

  @Test
  public void testDateFormatString() {
        GregorianCalendar calendar = new GregorianCalendar(utcTimeZone(), Locale.US);
        // Calendar was created with current time, must clear it
        calendar.clear();
        calendar.set(2018, Calendar.JUNE, 25);
        Date date = calendar.getTime();
        String dateStr = ISO8601Utils.format(date);
        String expectedDate = "2018-06-25";
        assertThat(dateStr.substring(0, expectedDate.length())).isEqualTo(expectedDate);
    }

  @Test
  public void testDateFormatWithMilliseconds() {
        long time = 1530209176870L;
        Date date = new Date(time);
        String dateStr = ISO8601Utils.format(date, true);
        String expectedDate = "2018-06-28T18:06:16.870Z";
        assertThat(dateStr).isEqualTo(expectedDate);
    }

  @Test
  public void testDateFormatWithTimezone() {
        long time = 1530209176870L;
        Date date = new Date(time);
        String dateStr = ISO8601Utils.format(date, true, TimeZone.getTimeZone("Brazil/East"));
        String expectedDate = "2018-06-28T15:06:16.870-03:00";
        assertThat(dateStr).isEqualTo(expectedDate);
    }

  @Test
  public void testDateParseWithDefaultTimezone() throws ParseException {
        String dateStr = "2018-06-25";
        Date date = ISO8601Utils.parse(dateStr, new ParsePosition(0));
        Date expectedDate = new GregorianCalendar(2018, Calendar.JUNE, 25).getTime();
        assertThat(date).isEqualTo(expectedDate);
    }

  @Test
  public void testDateParseInvalidDay() {
      String dateStr = "2022-12-33";
      try {
        ISO8601Utils.parse(dateStr, new ParsePosition(0));
        fail("Expected parsing to fail");
      } catch (ParseException expected) {
      }
    }

  @Test
  public void testDateParseInvalidMonth() {
      String dateStr = "2022-14-30";
      try {
        ISO8601Utils.parse(dateStr, new ParsePosition(0));
        fail("Expected parsing to fail");
      } catch (ParseException expected) {
      }
    }

  @Test
  public void testDateParseWithTimezone() throws ParseException {
        String dateStr = "2018-06-25T00:00:00-03:00";
        Date date = ISO8601Utils.parse(dateStr, new ParsePosition(0));
        GregorianCalendar calendar = createUtcCalendar();
        calendar.set(2018, Calendar.JUNE, 25, 3, 0);
        Date expectedDate = calendar.getTime();
        assertThat(date).isEqualTo(expectedDate);
    }

  @Test
  public void testDateParseSpecialTimezone() throws ParseException {
        String dateStr = "2018-06-25T00:02:00-02:58";
        Date date = ISO8601Utils.parse(dateStr, new ParsePosition(0));
        GregorianCalendar calendar = createUtcCalendar();
        calendar.set(2018, Calendar.JUNE, 25, 3, 0);
        Date expectedDate = calendar.getTime();
        assertThat(date).isEqualTo(expectedDate);
    }

  @Test
  public void testDateParseInvalidTime() {
        final String dateStr = "2018-06-25T61:60:62-03:00";
        assertThrows(ParseException.class, new ThrowingRunnable() {
          @Override
          public void run() throws Throwable {
            ISO8601Utils.parse(dateStr, new ParsePosition(0));
          }
        });
    }
}